As nanotechnology matures, providing more and more products with particles measured in nanometers, the risk of exposure to these particles needs to be assessed and regulated. Being able to determine what size of particles can be expelled by the body and what sizes accumulate in the body helps shape the questions for the regulatory landscape. But it doesn’t close off exploration into potential risks.

While other regulatory models can provide useful examples, it’s important to remember that the scale of these particles may provide unique concerns. I would hope that the hard lessons of chemical regulation – where accumulated exposure flew under the regulatory radar for years (see Krimsky’s Hormonal Chaos for a good overview), could be used to good effect here. It may not be enough that the small particles can be expelled. Enough transitory exposures over time could have unfortunate effects, much like enough small doses of certain chemicals have had dramatic effects on endocrine systems.